As background art references, there are Patent Literatures 1 and 2 and Non Patent Literature 1. The abstract of Patent Literature 1 describes as follows: A recording medium, and a method and apparatus for recording defect management information on the recording medium are disclosed. The method for recording defect management information of a recording medium includes recording a defect entry on the recording medium, wherein the defect entry includes a first field that can identify a defect entry type, a second field recording position information of a defect area within a user data area, and a third field recording position information of a spare area within an area for replacement, and recording position information corresponding to the second field and/or the third field in accordance with the defect entry type decided by the first field, wherein, in the case of a defect entry type having no corresponding position information, the corresponding field is set to zero (0).
Further, the abstract of Patent Literature 2 describes that the problem to be solved is “to make a write-once medium rewritable and to facilitate effective use of a main data area and increase in record/reproduce performance.” Further, the abstract describes the solution as follows:
In the write-once medium, a selected area, such as a postscript point in the main data area, is used for a replacement destination area. Moreover, sequential recording range information allows determination of whether recording has been made or not on a target address of a writing request and the like. Furthermore, replacement management information for defect replacement and data rewriting is integrated to coexist. This allows defect replacement and data rewriting without allocation of a fixed spare area. Moreover, when the spare area is allocated, if shortage occurs in the capacity usable for the replacement process in the spare area, the selected area such as the postscript point in the main data area is used for the replacement destination area.
Moreover, Non Patent Literature 1 discloses a technique related to a defect management method.